and
but it return all term in my taxonomy and i need to return current term in my taxonomy ..

UPDATE :

i finaly find this and add if for empty terms and works

<?php // Get terms for post
$terms = get_the_terms( $post->ID , 'oil' );
// Loop over each item since it's an array
if ( $terms != null ){
foreach( $terms as $term ) {
// Print the name method from $term which is an OBJECT
print $term->slug ;
// Get rid of the other data stored in the object, since it's not needed
unset($term);
} } ?>